Batteries are made of one or more cells, for example, lithium-ion cells or lithium-air cells, and are used to power many different types of devices. Rechargeable lithium batteries are attractive energy storage devices for portable electric and electronic devices. As the energy of batteries continues to rise, the potential for serious failures becomes a concern. Due to manufacturing variability, extreme operating conditions, exploitative usage and so on, a battery of the electronic may develop faults.
Catastrophic battery failure may include a thermal runaway event in which an internal short circuit inside a cell initiates a self-accelerating decomposition reaction inside the cell. The thermal runaway events may include smoke, flames, or even an explosion if an intervention is not performed in a timely manner.
In conventional systems, various mechanisms are available to detect short circuits in cells by monitoring cell voltages.
Voltage of a cell is monitored over time when there is no charge or discharge current flowing in the cell. A drop or decline in cell voltage beyond a certain value can indicate the presence of an internal short in the cell, thus allowing the cell to be rejected as faulty cell. However, such voltage tests do not identify cells that will develop internal short circuits later in their life cycle, which may lead to catastrophic failures of cells that develop internal short circuits during operation. Early detection of the fault is essential to ensure safe operation of the battery. Detection of fault inception due to battery internal short is difficult due to lack of prior information.
The above information is presented as background information only to help the reader to understand the present invention. Applicants have made no determination and make no assertion as to whether any of the above might be applicable as Prior Art with regard to the present application.